<ARTICLE> 5
<RESTATED> 
<MULTIPLIER> 1,000
       
                                                                           
<PERIOD-TYPE>                       3-MOS                   6-MOS                   9-MOS
<FISCAL-YEAR-END>                   DEC-31-1997             DEC-31-1997             DEC-31-1997
<PERIOD-START>                      JAN-01-1997             JAN-01-1997             JAN-01-1997
<PERIOD-END>                        MAR-31-1997             JUN-30-1997             SEP-30-1997
<CASH>                                    3,936                   4,149                   4,905
<SECURITIES>                            123,051                 143,618                 163,068
<RECEIVABLES>                            40,196                  44,365                  42,312
<ALLOWANCES>                              1,449                   1,558                   1,374
<INVENTORY>                              16,661                  14,539                  14,410
<CURRENT-ASSETS>                         69,412                  69,521                  75,653
<PP&E>                                  232,865                 235,315                 239,707
<DEPRECIATION>                           93,969                  96,285                  98,632
<TOTAL-ASSETS>                          395,906                 416,087                 443,368
<CURRENT-LIABILITIES>                    35,830                  30,787                  37,471
<BONDS>                                  62,517                  62,218                  59,914
<PREFERRED-MANDATORY>                         0                       0                       0
<PREFERRED>                                   0                       0                       0
<COMMON>                                 10,669                  10,669                  10,669
<OTHER-SE>                              224,379                 242,709                 228,654
<TOTAL-LIABILITY-AND-EQUITY>            395,906                 416,087                 443,368
<SALES>                                  59,614                 126,114                 188,922
<TOTAL-REVENUES>                            896                 127,907                 191,695
<CGS>                                    40,076                  81,327                 122,483
<TOTAL-COSTS>                            40,076                  81,327                 122,483
<OTHER-EXPENSES>                         12,988                  26,649                  39,505
<LOSS-PROVISION>                            286                     557                     791
<INTEREST-EXPENSE>                        1,382                   2,790                   4,147
<INCOME-PRETAX>                           5,778                  16,584                  24,769
<INCOME-TAX>                              1,897                   5,668                   8,454
<INCOME-CONTINUING>                       3,881                  10,916                  16,315
<DISCONTINUED>                                0                       0                       0
<EXTRAORDINARY>                               0                       0                       0
<CHANGES>                                     0                       0                       0
<NET-INCOME>                              3,881                  10,916                  16,315
<EPS-PRIMARY>                               .45<F1>                1.28<F1>                1.91<F1>
<EPS-DILUTED>                               .45<F1>                1.27<F1>                1.90<F1>
<FN>
<F1>Per share amounts are restated to reflect 2-for-1 stock split effective March
6, 1998 and adoption of FAS128 effective fourth quarter 1997.
</FN>